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Serge Van Calenbergh - One of the best experts on this subject based on the ideXlab platform.

Helene Munierlehmann - One of the best experts on this subject based on the ideXlab platform.

Piet Herdewijn - One of the best experts on this subject based on the ideXlab platform.

  • substrate dependence of competitive nucleotide pyrophosphatase phosphodiesterase1 npp1 inhibitors
    Frontiers in Pharmacology, 2017
    Co-Authors: Soumya Sarkar, Sanjay Bhattarai, Vigneshwaran Namasivayam, Ali Eltayeb, Holger Stephan, Steven De Jonghe, Piet Herdewijn, Christa E. Müller
    Abstract:

    Nucleotide pyrophosphatase / phosphodiesterase type 1 (NPP1) is a membrane glycoprotein involved in the hydrolysis of extracellular nucleotides. Its major substrate is ATP which is converted to AMP and diphosphate. NPP1 was proposed as a new therapeutic target in brain cancer and immuno-oncology. Several NPP1 inhibitors have been reported to date, most of which were evaluated versus the artificial substrate p-nitrophenyl 5’-Thymidine Monophosphate (p-Nph-5’-TMP). Recently, we observed large discrepancies in inhibitory potencies for a class of competitive NPP1 inhibitors when tested versus the artificial substrate p-Nph-5’-TMP as compared to the natural substrate ATP. Therefore, the goal of the present study was to investigate whether inhibitors of human NPP1 generally display substrate-dependent inhibitory potency. Systematic evaluation of nucleotidic as well as non-nucleotidic NPP1 inhibitors revealed significant differences in determined Ki values for competitive, but not for non- and un-competitive inhibitors when tested versus the frequently used artificial substrate p-Nph-5’-TMP as compared to ATP. Allosteric modulation of NPP1 by p-Nph-5’-TMP may explain these discrepancies. Results obtained using the AMP derivative p-nitrophenyl 5’-adenosine Monophosphate (p-Nph-5’-AMP) as an alternative artificial substrate correlated much better with those employing the natural substrate ATP.

  • imidazopyridine and purine thioacetamide derivatives potent inhibitors of nucleotide pyrophosphatase phosphodiesterase 1 npp1
    Journal of Medicinal Chemistry, 2014
    Co-Authors: Lei Chang, Piotr Leonczak, Theodor Hanck, Christa E. Müller, Steven De Jonghe, Jef Rozenski, Piet Herdewijn
    Abstract:

    Nucleotide pyrophosphatase/phosphodiesterase 1 (NPP1) belongs to the family of ecto-nucleotidases, which control extracellular nucleotide, nucleoside, and (di)phosphate levels. To study the (patho)physiological roles of NPP1 potent and selective inhibitors with drug-like properties are required. Therefore, a compound library was screened for NPP1 inhibitors using a colorimetric assay with p-nitrophenyl 5′-Thymidine Monophosphate (p-Nph-5′-TMP) as an artificial substrate. This led to the discovery of 2-(3H-imidazo[4,5-b]pyridin-2-ylthio)-N-(3,4-dimethoxyphenyl)acetamide (5a) as a hit compound with a Ki value of 217 nM. Subsequent structure–activity relationship studies led to the development of purine and imidazo[4,5-b]pyridine analogues with high inhibitory potency (Ki values of 5.00 nM and 29.6 nM, respectively) when assayed with p-Nph-5′-TMP as a substrate. Surprisingly, the compounds were significantly less potent when tested versus ATP as a substrate, with Ki values in the low micromolar range. A prot...

  • Synthesis and evaluation of 6-aza-2'-deoxyuridine Monophosphate analogs as inhibitors of thymidylate synthases, and as substrates or inhibitors of Thymidine Monophosphate kinase in Mycobacterium tuberculosis.
    Chemistry and Biodiversity, 2012
    Co-Authors: Martin Kögler, Steven De Jonghe, Jef Rozenski, Hélène Munier-lehmann, Roger Busson, Kristien Van Belle, Thierry Louat, Piet Herdewijn
    Abstract:

    A series of 5-substituted analogs of 6-aza-2'-deoxyuridine 5'-Monophosphate, 6-aza-dUMP, has been synthesized and evaluated as potential inhibitors of the two mycobacterial thymidylate synthases (i.e., a flavin-dependent thymidylate synthase, ThyX, and a classical thymidylate synthase, ThyA). Replacement of C(6) of the natural substrate dUMP by a N-atom in 6-aza-dUMP 1a led to a derivative with weak ThyX inhibitory activity (33% inhibition at 50 μM). Introduction of alkyl and aryl groups at C(5) of 1a resulted in complete loss of inhibitory activity, whereas the attachment of a 3-(octanamido)prop-1-ynyl side chain in derivative 3 retained the weak level of mycobacterial ThyX inhibition (40% inhibition at 50 μM). None of the synthesized derivatives displayed any significant inhibitory activity against mycobacterial ThyA. The compounds have also been evaluated as potential inhibitors of mycobacterial Thymidine Monophosphate kinase (TMPKmt). None of the derivatives showed any significant TMPKmt inhibition. However, replacement of C(6) of the natural substrate (dTMP) by a N-atom furnished 6-aza-dTMP (1b), which still was recognized as a substrate by TMPKmt.

  • Discovery of bicyclic Thymidine analogues as selective and high-affinity inhibitors of Mycobacterium tuberculosis Thymidine Monophosphate kinase.
    Journal of Medicinal Chemistry, 2004
    Co-Authors: Veerle Vanheusden, Jef Rozenski, Piet Herdewijn, Hélène Munier-lehmann, Matheus Froeyen, Roger Busson, Serge Van Calenbergh
    Abstract:

    Thymidine Monophosphate kinase of Mycobacterium tuberculosis (TMPKmt) represents an attractive target for selectively blocking bacterial DNA synthesis. Hereby, we report on the discovery of a novel class of bicyclic nucleosides (10 and 11) and one dinucleoside (12), belonging to the most selective inhibitors of TMPKmt discovered so far.

  • Thymidine and Thymidine 5 o Monophosphate analogues as inhibitors of mycobacterium tuberculosis thymidylate kinase
    Bioorganic & Medicinal Chemistry Letters, 2003
    Co-Authors: Veerle Vanheusden, Piet Herdewijn, Helene Munierlehmann, Sylvie Pochet, Philippe Van Rompaey, Serge Van Calenbergh
    Abstract:

    The affinity of a series of 2', 3'- and 5-modified Thymidine analogues for Mycobacterium tuberculosis Thymidine Monophosphate kinase (TMPKmt) was evaluated. The affinities of several non-phosphorylated analogues are in the same order of magnitude as those of their phosphorylated congeners. In view of drug delivery problems associated with phosphorylated compounds, these 'free' nucleosides seem more promising leads in the search of TMPKmt inhibitors as novel anti-tuberculosis agents.

Hélène Munier-lehmann - One of the best experts on this subject based on the ideXlab platform.

  • Synthesis of sulfamide analogues of deoxThymidine Monophosphate as potential inhibitors of mycobacterial cell wall biosynthesis
    Carbohydrate Research, 2018
    Co-Authors: Kajitha Suthagar, Wanting Jiao, Hélène Munier-lehmann, Antony Fairbanks
    Abstract:

    The recently discovered enzyme Mycobacterium tuberculosis Thymidine Monophosphate kinase (TMPKmt), which catalyses the phosphorylation of deoxyThymidine Monophosphate (dTMP) to give deoxyThymidine diphosphate (dTDP), is indispensable for the growth and survival of M. tuberculosis as it plays an essential role in DNA synthesis. Inhibition of TMPKmt is an attractive avenue for the development of novel anti-tuberculosis agents. Based on the premise that sulfamide may be a suitable isostere of phosphate, deoxyThymidine analogues comprising various substituted sulfamides at C5′ were modelled in silico into the active site of TMPKmt (PDB accession code: 1N5K) using induced-fit docking methods. A selection of modelled compounds was synthesized, and their activity as inhibitors of TMPKmt was evaluated. Three compounds showed competitive inhibition of TMPKmt in the micromolar range (10–50 μM). Compounds were tested in vitro for anti-mycobacterial activity against M. smegmatis: three compounds showed weak anti-mycobacterial activity (MIC 250 μg/mL).

  • Tetrahydro-2-furanyl-2,4(1H,3H)-pyrimidinedione derivatives as novel antibacterial compounds against Mycobacterium
    Wolters Kluwer Medknow Publications, 2017
    Co-Authors: Yuji Koseki, Hélène Munier-lehmann, Hironori Kanetaka, Joji Tsunosaki, Shunsuke Aoki
    Abstract:

    Objective/Background: Mycobacterium tuberculosis Thymidine Monophosphate kinase (mtTMPK) is a potential enzymatic target for the treatment of tuberculosis (TB). Materials and Methods: In this study, we performed pharmacophore-based in silico screening, targeting mtTMPK with a compound library of 461,383 chemicals. We evaluated the candidate compounds for inhibitory effects on the growth of the model mycobacteria, Mycobacterium smegmatis. Results: The compound KTP3 completely inhibited the growth of M. smegmatis at 100 μM. A similarity search and rescreening with the structure of compound KTP3 using a web-based database identified two similar compounds (KTPS1 and KTPS2) with improved potency. The KTP3 analogs, KTPS1 and KTPS2, exhibited strong growth inhibitory effects with half-maximal inhibitory concentration values of 8.04 μM and 17.1 μM, respectively, against M. smegmatis. Moreover, the most potent chemical compound, KTPS1, did not exhibit toxic effects on the model enterobacteria and several mammalian cells. Two active chemicals, KTPS1 and KTPS2, inhibited mtTMPK activity by 18% and 36%, respectively, suggesting that these compounds have off-target activities against Mycobacterium. Conclusion: Structural and biological information on these chemicals is likely to be useful for the development of novel antibiotics for the treatment of TB

  • Synthesis and evaluation of 6-aza-2'-deoxyuridine Monophosphate analogs as inhibitors of thymidylate synthases, and as substrates or inhibitors of Thymidine Monophosphate kinase in Mycobacterium tuberculosis.
    Chemistry and Biodiversity, 2012
    Co-Authors: Martin Kögler, Steven De Jonghe, Jef Rozenski, Hélène Munier-lehmann, Roger Busson, Kristien Van Belle, Thierry Louat, Piet Herdewijn
    Abstract:

    A series of 5-substituted analogs of 6-aza-2'-deoxyuridine 5'-Monophosphate, 6-aza-dUMP, has been synthesized and evaluated as potential inhibitors of the two mycobacterial thymidylate synthases (i.e., a flavin-dependent thymidylate synthase, ThyX, and a classical thymidylate synthase, ThyA). Replacement of C(6) of the natural substrate dUMP by a N-atom in 6-aza-dUMP 1a led to a derivative with weak ThyX inhibitory activity (33% inhibition at 50 μM). Introduction of alkyl and aryl groups at C(5) of 1a resulted in complete loss of inhibitory activity, whereas the attachment of a 3-(octanamido)prop-1-ynyl side chain in derivative 3 retained the weak level of mycobacterial ThyX inhibition (40% inhibition at 50 μM). None of the synthesized derivatives displayed any significant inhibitory activity against mycobacterial ThyA. The compounds have also been evaluated as potential inhibitors of mycobacterial Thymidine Monophosphate kinase (TMPKmt). None of the derivatives showed any significant TMPKmt inhibition. However, replacement of C(6) of the natural substrate (dTMP) by a N-atom furnished 6-aza-dTMP (1b), which still was recognized as a substrate by TMPKmt.

  • Drug design and identification of potent leads against Mycobacterium tuberculosis Thymidine Monophosphate kinase.
    Current Topics in Medicinal Chemistry, 2012
    Co-Authors: S. Van Calenbergh, Sylvie Pochet, Hélène Munier-lehmann
    Abstract:

    Antiviral chemotherapy often relies on nucleoside analogues, which, once phophorylated by intracellular kinases, target viral polymerases impeding DNA synthesis. In contrast, nucleoside analogues are much less explored as antibacterial drugs. Thymidine Monophosphate kinase from Mycobacterium tuberculosis (TMPKmt), which is essential to DNA replication, was selected as a promising target for the design of new inhibitors. This review describes stepwise modifications of the TMPKmt substrate, guided by the feedback of enzyme assays and crystallographic analysis to afford potent enzyme inhibitors some of which also exhibited antitubercular activity. More importantly, several of the reported Thymidine analogues provided a deeper understanding of the structure and catalytic mechanism of this intriguing enzyme.

  • Synthesis and inhibitory activity of Thymidine analogues targeting Mycobacterium tuberculosis Thymidine Monophosphate kinase.
    Bioorganic and Medicinal Chemistry, 2011
    Co-Authors: Sara Van Poecke, Hélène Munier-lehmann, Matheus Froeyen, Olivier Helynck, Serge Van Calenbergh
    Abstract:

    We report on Mycobacterium tuberculosis Thymidine Monophosphate kinase (TMPKmt) inhibitory activities of a series of new 3'- and 5'-modified Thymidine analogues including α- and β-derivatives. In addition, several analogues were synthesized in which the 4-oxygen was replaced by a more lipophilic sulfur atom to probe the influence of this modification on TMPKmt inhibitory activity. Several compounds showed an inhibitory potency in the low micromolar range, with the 5'-arylthiourea 4-thio-α-Thymidine analogue being the most active one (K(i)=0.17μM). This compound was capable of inhibiting mycobacteria growth at a concentration of 25μg/mL.

Sylvie Pochet - One of the best experts on this subject based on the ideXlab platform.